PA PI LION A CEA E. 555 



4. Homalobus caespitosus Nutt. TUFTED MILK VETCH. (I. F. f. 2153.) 

 Silvery-canescent, tufted from a deep root, 7-15 cm. high. Stipules scarious, im- 

 bricated, lanceolate, acuminate, 8-12 mm. long; leaves simple, spatulate-linear, 

 2.5-5 cm. long, or some of them 3-5-foliolate, with oblong-linear leaflets; peduncles 

 scapiform; flowers purple, 911 mm. long, in short spike-like racemes; pod erect, 

 sessile, few-seeded, oblong, acute, coriaceous, slightly curved, pubescent, 9-11 mm. 

 long; calyx-teeth subulate. In dry rocky soil, Neb. and Colo, to the N. W. Terr. 

 May-July. 



26. OROPHACA Britton. 



Perennial, silvery or villous-pubescent low tufted herbs, with branched woody 

 caudices, deep roots, membranous scarious stipules, sheathing and united below, 

 and digitately 3-foliolate (rarely 5-foliolate) leaves, resembling those of Lupines. 

 Flowers few, capitate or racemose, the clusters sessile or peduncled. Keel of the 

 corolla blunt. Pod coriaceous, completely I -celled, ovoid or oval, few-seeded, 

 villous, partly or wholly enclosed by the calyx. [Greek, mountain vetch.] Three 

 known species, the following, and one in Colo, and Wyo. 



Flowers yellowish, 1-3 together in the axils. i. O. caespitosa. 



Flowers blue-purple, in peduncled racemes. 2. O. sertcea. 



1. Orophaca caespitosa (Nutt.) Britton. SESSILE-FLOWERED MILK VETCH. 

 (I. F. f. 2154.) Silvery-canescent, 5-10 cm. high. Stipules imbricated, glabrous, 

 ovate-lanceolate, 6-9 mm. long; leaves digitately 3-5-foliolate, slender-petioled; 

 leaflets oblong or oblanceolate, narrowed or cuneate at the base, 13-17 mm. long; 

 flowers 13-17 mm. long, sessile; pod sessile, ovoid, acute or acuminate, coriace- 

 ous, dehiscent, enclosed by the calyx, 4-6 mm. long. Plains, Kans, to S. Dak., 

 Mont, and the N. W. Terr. May-July. 



2. Orophaca sericea (Nutt.) Britton. HOARY MILK VETCH. (I. F. f. 2155.) 

 Villous-pubescent, spreading on the ground, the stems 8-10 cm. long. Leaves 

 short-petioled, 3-foliolate; leaflets oblong or oblanceolate, narrowed or cuneate at 

 the base, 4-11 mm. long; peduncles 2-6-flowered; flowers about 6 mm. long; pod 

 sessile, ovoid-oblong, coriaceous, acute, about 6 mm. long, partly enclosed by the 

 calyx. In dry, sandy or rocky places, Neb. and Colo. May-July. 



27. ARAGALLUS Neck. [SPIESIA Neck.] 



Herbs, sometimes shrubby, and mostly acaulescent, with odd-pinnate leaves, 

 and racemose or spicate flowers. Calyx-teeth nearly equal. Petals clawed; 

 standard erect, ovate or oblong ; wings oblong ; keel erect, shorter than or equalling 

 the wings, its apex mucronate. acuminate or appendaged; stamens diadelphous; 

 style filiform. Pod sessile or stipitate, 2-valved, I -celled, or more or less 2-celled 

 by the intrusion of the ventral suture. About 120 species of the north temperate 

 zone. In addition to the following, some n others occur in western N. Am. 



Leaves simply pinnate. 



Plants 2.5-10 cm. high ; heads few-flowered. 



Pods membranous, pubescent, much inflated, i-celled. i. A. inflatus. 

 Pod coriaceous, ovoid, little inflated, pubescent, partly 2-celled. 



Calyx gray-pubescent ; leaflets 7-9, oblong. 2. A. multiceps. 



Calyx dark-pubescent; leaflets 7-21, linear. 3. A. arcticus. 

 Plants 1.5-4.5 dm. high ; heads or spike-like racemes many-flowered. 

 Flowers 17-19 mm. long ; pods papery. 



Calyx black-hirsute ; pod about i cm. long. 4. A. campestris. 



Calyx finely pubescent ; pod 15-20 mm. long. 5. A. Johannensis. 

 Flowers 19-30 mm. long ; pods coriaceous. 



Leaflets linear or linear-lanceolate, slightly silky. 6. A. Lambcrtti. 



Leaflets oblong or broadly lanceolate, densely silky. 7. A. sertceus. 

 Leaves pinnate, the leaflets verticillate. 



Pod scarcely longer than the calyx, its tip spreading. 8. A. splendens. 



Pod 2-3 times as long as the calyx, its tip erect. 9. A. Bellii. 



I. Aragallus inflatus (Hook.) A. Nelson. INFLATED OXYTROPE. (I. F. f. 

 2156.) Acaulescent or nearly so, villous-pubescent, much tufted, 2-10 cm. high. 

 Stipules membranous, imbricated, adnate to the petiole, lanceolate, about 4 mm. 

 long; leaflets 9-21, linear, 4-8 mm. long, about I mm. wide, obtuse or obtusish; 



